/**

* Difficulty:

* Medium

*

* Desc:

* Determine if a Sudoku is valid, according to: Sudoku Puzzles - The Rules: http://sudoku.com.au/TheRules.aspx

* The Sudoku board could be partially filled, where empty cells are filled with the character '.'.

*

* 检查数独棋盘上的数字是否合法。还没有填充的数字用 '.' 表示

* 注意：

* 输入为 9 * 9 的数组

* [

* [".", ".", ".", ".", "5", ".", ".", "1", "."],

* [".", "4", ".", "3", ".", ".", ".", ".", "."],

* [".", ".", ".", ".", ".", "3", ".", ".", "1"],

* ["8", ".", ".", ".", ".", ".", ".", "2", "."],

* [".", ".", "2", ".", "7", ".", ".", ".", "."],

* [".", "1", "5", ".", ".", ".", ".", ".", "."],

* [".", ".", ".", ".", ".", "2", ".", ".", "."],

* [".", "2", ".", "9", ".", ".", ".", ".", "."],

* [".", ".", "4", ".", ".", ".", ".", ".", "."]

* ]

* 其中，从 (0, 0) 到 (2, 2) 的 3 * 3 方格内表示宫1，并可由此类推

*/

/**

* 利用数组规则，检查每行、每列、每宫内的数字是否合法（不能有重复）

*/

/**

* @param {character[][]} board

* @return {boolean}

*/

var isValidSudoku = function(board) {

var data = {};

var boxData = {};

var validate = true;

for (var i = 0; i < board.length; i += 1) {

var box = board[i];

var rowId = `r${i + 1}`;

var boxRow = Math.floor(i / 3) + 1;

var numbers = box.filter(item => item !== '.');

if (new Set(numbers).size < numbers.length) {

validate = false;

break;

}

for (var j = 0; j < box.length; j += 1) {

var columnId = `c${j + 1}`;

var boxColumn = Math.floor(j / 3) + 1;

var boxId = `b${(boxRow - 1) * 3 + boxColumn}`;

if (!data[columnId]) {

data[columnId] = new Set();

}

if (!data[rowId]) {

data[rowId] = new Set();

}

var num = box[j];

if (num === '.') continue;

if (data[columnId].has(num) || data[rowId].has(num)) {

validate = false;

break;

}

data[columnId].add(num);

data[rowId].add(num);

if (!boxData[boxId]) {

boxData[boxId] = [];

}

boxData[boxId].push(num);

}

if (!validate) break;

}

if (!validate) return validate;

for (var i = 0; i < Object.keys(boxData).length; i += 1) {

var box = boxData[Object.keys(boxData)[i]];

if (box.length > new Set(box).size) {

validate = false;

break;

}

}

return validate;

};